Flammability and flame retardation of various polymers are reviewed. The important items discussed in this paper are Oxygen Index and Smoke Density Rating which are used for the measurement of flammability, flame retardants and their mechanism which transform flammable polymers into non-flammable ones, processing methods for flame retardation, testing methods of flammability and the price trend of flame retardants. Index has some actual formulations of fire retardant paint, fire retardant resin and flame retardant fiber.

In this last part of review series intermediate and high temperature application of solar concentrator, solar thermal power generation, and solar photovoltaic conversion are described. At higher temperatures efficient and large-scale industrial utilization of solar energy are expected by generating electricity. However, since R&D works on these fields require large investment and highly advanced technology, economic and technical feasibility is not forseeable in the near future.

Mass transfer characteristics were investigated in a counter-current bubble column packed with cylindrical screen rings and correlated with the axial dispersion coefficient measured by an impulse response technique. Absorption of by water in the column was used for this investigation. The volumetric coefficient of liquid phase mass transfer was found to increase with increasing superficial gas velocity and axial dispersion coefficient of liquid. The relationship could be expressed by the following correlation:

In the production of polyethylene under high pressure, yielding so called “low-density polyethylene”, control of the long-chain branching reaction is of paramount importance to product quality. This is because the long-chain branching level influences the rheological properties and processability of the polyethylene produced. The high pressure polyethylene tubular reactor is characterized by its large length-to-diameter ratio which ranges from 250 : 1 to as high as 1200 : 1. Since a significant portion of the production cost of polyethylene in a high-pressure tubular reactor is attributed to the power consumption needed to compress the ethylene, an increase in conversion should help reduce the production cost considerably. It has been suggested in the literature that the use of multiple injections of initiator and/or monomer can increase the conversion of ethylene considerably. We have recently investigated the performance (the conversion and product quality) of a high-pressure polyethylene tubular reactor with multiple injections of initiator and monomer. As part of the investigation, temperature profiles, monomer and initiator conversion, and the number-and weight-average molecular weights were calculated along the length of the reactor. In this paper, we shall present some of the highlights of the study.

An equation of state, which can best represent the P-V-T data ethylene gas below the critical point (, 51 bar), and its coefficients were determined by means of the non-linear least-squares technique using recently published experimental data. A total of 90 data points, ranging temperature and below 50 bar pressure, were fitted to the modified Bender equation and the coefficients of the 6-parameter and 10-parameter equations were obtained. The RMS deviations of the calculated densities are 0.1% from the experimental data used in this curve fitting, and 0.15% from Michels data. Therefore these equations of state can be used within the experimental range with a probable error of .

The recovery of low temperature geothermal energy () in Korea is investigated by injecting air seasonally for local community heating without heat exchangers, when a gas storage development is planned. A preliminary design was conducted to study the feasibility of the scheme. Safety, economics, reserve estimation, and aquifer dynamics were studied. Other recovery methods and power generation have been briefly reviewed. Conversion to a small gas storage system upon depletion of geothermal energy, because of the Korea's pressing need for underground storage system and the overall economic advantage, plays a very significant role to make the energy recovery attractive.